A certain orbital has no angular nodes and two radial nodes. The orbital is :

Given below are two statements : Statement I : Bohr's theory accounts for the stability and line spectrum of Li+ ion. Statement II : Bohr's theory was unable to explain the splitting of spectral lines in the presence of a magnetic field. In the light of the above statements, choose the most appropriate answer from the options given below :

Outermost electronic configuration of a group 13 element, E, is 4s2, 4p1. The electronic configuration of an element of p-block period-five placed diagonally to element, E is :

Given below are two statements : Statement I : Rutherford's gold foil experiment cannot explain the line spectrum of hydrogen atom. Statement II : Bohr's model of hydrogen atom contradicts Heisenberg' uncertainty principle. In the light of the above statements, choose the most appropriate answer from the options given below :

If the Thompson model of the atom was correct, then the result of Rutherford's gold foil experiment would have been :

Given below are two statements. Statement I : According to Bohr's model of an atom, qualitatively the magnitude of velocity of electron increases with decrease in positive charges on the nucleus as there is no strong hold on the electron by the nucleus. Statement II : According to Bohr's model of an atom, qualitatively the magnitude of velocity of electron increases with decrease in principal quantum number. In the light of the above statements, choose the most appropriate answer from the options given below :

Consider the elements Mg, Al, S, P and Si, the correct increasing order of their first ionization enthalpy is :

The correct order of bond dissociation enthalpy of halogens is :

Match List - I with List - II. List I Electronic configuration List II $${\Delta }_{i}H$$ in kJ $$mo{l}^{-1}$$ (a) $$1s^{2}2s^2$$ (i) 801 (b) $$1s^{2}2s^{2}2p^4$$ (ii) 899 (c) $$1s^{2}2s^{2}2p^3$$ (iii) 1314 (d) $$1s^{2}2s^{2}2p^1$$ (iv) 1402 Choose the most appropriate answer from the options given below :

Which pair of oxides is acidic in nature?

The correct order of electron gain enthalpy is :

The characteristics of elements X, Y and Z with atomic numbers, respectively, 33, 53 and 83 are :

Identify the elements X and Y using the ionisation energy values given below : Ionization energy (kJ/mol) 1$$st$$ 2$$nd$$ X 495 4563 Y 731 1450

The absolute value of the electron gain enthalpy of halogens satisfies :

The ionic radius of Na+ ions is 1.02 $$\stackrel{o}{A}$$. The ionic radii (in $$\stackrel{o}{A}$$) of Mg2+ and Al3+, respectively, are

The first ionization energy of magnesium is smaller as compared to that of elements X and Y, but higher than that of Z. The elements X, Y and Z, respectively, are :

Which one of the following statements for D.I. Mendeleeff, is incorrect?

The ionic radii of K+, Na+, Al3+ and Mg2+ are in the order:

The ionic radii of F$$-$$ and O2$$-$$ respectively are 1.33$$\stackrel{o}{A}$$ and 1.4$$\stackrel{o}{A}$$, while the covalent radius of N is 0.74$$\stackrel{o}{A}$$. The correct statement for the ionic radius of N3$$-$$ from the following is :

Match List - I with List - II : List - I List - II (a) NaOH (i) Acidic (b) $$Be(OH{)}_2$$ (ii) Basic (c) $$Ca(OH{)}_2$$ (iii) Amphoteric (d) $$B(OH{)}_3$$ (e) $$Al(OH{)}_3$$ Choose the most appropriate answer from the options given below